共查询到19条相似文献,搜索用时 171 毫秒
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运动估计中菱形算法是一种高效的搜索方法,但它没有利用视频序列中运动矢量的中心偏置分布特性和相邻宏块在时间和空间上的相关性,因此还有很大的空间可以进一步提高该算法的性能.在充分利用运动矢量的中心偏置分布特性和相邻宏块运动矢量的相关性的基础上,提出了一种基于自适应预测的菱形搜索算法(APDS),与传统的起点预测方法不同的是,该算法对所有宏块搜索起点的预测并不是按照一种固定的方法求取,而是通过分析其相邻宏块运动矢量的特性来自适应求得搜索起点和决定搜索策略.实验证明,同传统的菱形法相比,这种方法提高了搜索准确度,同时大幅降低了搜索时间,是一种高效率的搜索算法. 相似文献
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运动估计算法是实时视频编解码技术的研究重点,高精度的匹配和补偿可以减少预测误差,提高视频图像的压缩效果.为降低在视频编码标准H.264中运动估计的高计算复杂度问题,提出了采用一种基于节点模型的可变形块匹配运动估计算法来搜索最佳运动矢量.该算法充分利用了H.264运动矢量的的统计特性和相关性,并采用基于像素差值分类的运动估计匹配准则.实验表明,在编码性能损失很小的条件下,该算法有效降低了视频压缩编码中运动估计的运算复杂度. 相似文献
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文章提出一种直接对压缩视频码流进行全局运动估计的新算法。为了提高估计精度和计算效率.提出一种新的视频背景前景分割方法,该算法利用运动矢量和AC系数实现背景与前景分割。基于分割的结果,采用背景宏块的运动矢量进行全局运动参数估计。实验验证了提出的全局运动估计算法的计算效率和精度。 相似文献
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运动补偿插帧是目前主要的帧率上转换方法。为减小内插帧中的块效应,并降低运算量以满足实时高清视频应用,该文提出了一种基于3维递归搜索(3-D Recursive Search, 3-D RS)的多级块匹配运动估计视频帧率上转换算法。该算法将3-D RS与双向运动估计相结合,首先对序列中相邻帧进行由粗到精的三级运动估计,再利用简化的中值滤波器平滑运动矢量场,最后通过线性插值补偿得到内插帧。实验结果表明,与现有的运动补偿插帧算法相比,该算法内插帧的主、客观质量都有所提高,且算法复杂度低,有很强的实用性。 相似文献
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在新一代视频压缩编码标准H.264中,块匹配运动估计有着举足轻重的地位,它的性能影响着输出码流的质量。在块匹配中运动估计耗时最多,为了减少运动估计的时间和搜索的次数,常采用快速搜索算法。介绍块匹配运动表示法,详细研究块匹配中的3种快速搜索算法的搜索过程,并对3种算法的性能作比较分析。 相似文献
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To deal with the problem of restoring degraded images with non-Gaussian noise, this paper proposes a novel cooperative neural fusion regularization (CNFR) algorithm for image restoration. Compared with conventional regularization algorithms for image restoration, the proposed CNFR algorithm can relax need of the optimal regularization parameter to be estimated. Furthermore, to enhance the quality of restored images, this paper presents a cooperative neural fusion (CNF) algorithm for image fusion. Compared with existing signal-level image fusion algorithms, the proposed CNF algorithm can greatly reduce the loss of contrast information under blind Gaussian noise environments. The performance analysis shows that the proposed two neural fusion algorithms can converge globally to the robust and optimal image estimate. Simulation results confirm that in different noise environments, the proposed two neural fusion algorithms can obtain a better image estimate than several well known image restoration and image fusion methods. 相似文献
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Motion estimation is one of the critical parts in video compression standards with a high computational load. Many motion estimation algorithms have been developed to reduce the number of search points compared to a full-search algorithm without losing the quality considerably. Most of them use fixed search patterns in their first step which may suffer from trapping into local minima or searching unnecessary blocks due to inappropriate size and type of search patterns. In this paper, a new dynamic search pattern using motion vectors of spatial and temporal neighboring blocks is proposed. The motion vectors of neighboring blocks are prioritized, in order to efficiently use of halfway stop technique. The simulation results indicate that proposed algorithm is very close to the full-search algorithm in quality, compared to other rivals. Moreover, the average number of searches is often less than other algorithms. 相似文献
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In order to reduce the computation load, many conventional fast block-matching algorithms have been developed to reduce the set of possible searching points in the search window. All of these algorithms produce some quality degradation of a predicted image. Alternatively, another kind of fast block-matching algorithms which do not introduce any prediction error as compared with the full-search algorithm is to reduce the number of necessary matching evaluations for every searching point in the search window. The partial distortion search (PDS) is a well-known technique of the second kind of algorithms. In the literature, many researches tried to improve both lossy and lossless block-matching algorithms by making use of an assumption that pixels with larger gradient magnitudes have larger matching errors on average. Based on a simple analysis, it is found that, on average, pixel matching errors with similar magnitudes tend to appear in clusters for natural video sequences. By using this clustering characteristic, we propose an adaptive PDS algorithm which significantly improves the computation efficiency of the original PDS. This approach is much better than other algorithms which make use of the pixel gradients. Furthermore, the proposed algorithm is most suitable for motion estimation of both opaque and boundary macroblocks of an arbitrary-shaped object in MPEG-4 coding. 相似文献